DESCRIPTION: Cerebral edema and elevated intracranial pressure subsequent to traumatic brain injury (TBI) is a life-threatening complication that is refractory to conventional treatments in a significant population of patients. Current treatments (i.e. hyperventilation, osmotic diuretic(s) or barbiturates are themselves associate with serious side effects that increase with prolonged use. In this Phase I proposal in vitro and ex vivo, brain tissue experiments will be performed to determine the optimal design (fiber types construction materials) and operational (pressure gradients) characteristics for consistent fluid flux through microdialysis probes. Subsequent feasibility experiments, using a rodent model of TBI, will be conducted to establish optimal characteristics (probe designs, pressure gradients) and treatment parameters (time and duration of treatment) for using this novel therapeutic microdialysis technology to safely and efficiently reduce cerebral edema. Successful development and marketing of this proprietary methodology could significantly reduce morbidity and mortality in human TBI as well as in other neurological disorders where cerebral edema is a factor. In Phase II, further optimization and testing (rodent and porcine models of TBI) of catheter designs, a human pilot study, and manufacturing of therapeutic microdialysis systems are planned. PROPOSED COMMERCIAL APPLICATION: Therapeutic MicroDialysis plans to manufacture and market a microdialysis system for the treatment of cerebral edema in patients with severe TBI. The contemplated product is a self-contained unit with a disposable grouping of microdialysis fibers attached to a manifold which can be attached to optional sources of suction. The product will enable drainage and containment of interstitial edema fluid, protecting staff from exposure to body fluids and aiding in infection control. A conservative market potential for microdialysis catheters in TBI patients is estimated at $20 million (US) to $40 million (including international).